$2.$ Two long parallel wires $\backslash ($ X $\backslash )$ and $\backslash ($ Y $\backslash )$ carry equal currents $\backslash ($ I $\backslash ).$ The magnetic force exerted per unit length of each wire is $\backslash ($ F $\backslash ).$

The current in X is halved and the current in Y is doubled. What is the force per unit length of each wire after the change?

C$.$

D$.$

$\backslash [$

$\backslash$begin$\{$array$\}\{$ll$\}$

$2$ F & $2$ F

$\backslash$end$\{$array$\}$

$\backslash ]$